Envío 661

Código

n = int(input())
nums = list(map(int, input().split()))
left = [0 for x in range(n)]
right = [0 for x in range(n)]
left[0] = nums[0]
right[0] = nums[n - 1]
for i in range(1, n):
    left[i] = left[i - 1] + nums[i]
for i in reversed(range(n - 2)):
   right[i] = right[i + 1] + nums[i]
flag = True
for i in range(n - 1):
    if left[i] > 0 and right[i + 1] < 0:
        print(i + 1)
        break
if flag:
    print("Impossible")